that perfect pectoriloquy gradually becomes imperfect, that this imperfect pectoriloquy gradually merges into bronchophony, and bronchophony into the ordinary state of the voice, as heard generally over the parietes of the chest, there are some varieties, in respect to the thoracic voice, which are worthy of attentive consideration. Thus it is very generally rather more distinct upon the right side, and particularly below the right clavicle and over the right scapula, than in similar situations upon the left side. This may, I believe, be regarded as the rule, though some exceptions occasionally occur. The voice is also much more resonant in some persons than in others. a shrill or acute voice is generally more distinctly audible than one which is hoarse or grave. It is usually also louder in thin persons than in those whose integuments are loaded with fat, or infiltrated with serum, and, the power of the voice being equal, and both free from disease, it is more resonant in persons with contracted chests than in those in whom the thoracic cavity is largely developed. It is generally more distinct, cæteris paribus, in females than in males, probably from the greater shrillness of the voice in the former than in the latter.

Thus

In some few persons indeed-most commonly females-the voice is, in certain situations, as below the clavicles, or over the scapulæ, so clear, distinct, and loud, as to approach, if not to

attain, the character of imperfect pectoriloquy. Hence arises the necessity of the caution in allexaminations of the voice, always to compare the corresponding parts of opposite sides with each other. If after such comparison both sides be found equal, or nearly equal, in resonance, and if after minute examination no other physical signs of disease can be discovered, the unusual resonance may be ascribed with tolerable safety to natural peculiarity.

In consequence of some tones or syllables being better conducted than others (and it is remarkable that it is not always the same tones which in different persons possess this superiority), it is desirable that the same words or syllables should be pronounced during the examination of every part and of each side. It is on this account that it is usual to desire the person under examination to repeat the numerals, one, two, three, four, &c., as in them little or no variety is likely to occur.

7. Auscultation of the Organs of Respiration in Disease.

It will be found convenient in examining the phenomena afforded by auscultation in disease, as in the healthy condition of the respiratory organs, first to confine attention to the sounds, which coincide with the breathing itself, and after

wards to consider the alterations which take place in the voice and cough.

1. Of the Respiration in Disease.

It cannot be too forcibly impressed upon the mind of the student, and it may therefore be here again brought to his recollection, that there are few, very few single signs, if indeed there be any, which are purely characteristic or pathognomonic of disease. The more he observes for himself, and the more attentively he studies the products of disease, the more convinced will he become of this truth. Auscultation and its handmaid arts often enable us, with almost perfect certainty, to predict various morbid changes, but of the nature of those changes they tell us little or nothing. Physical signs merely indicate certain physical states, which may be produced by two, or by a variety of causes. The physical condition of the organs may be very generally detected by auscultation, and the other different modes of exploration treated of in this work; but information in respect to the morbid process by which it has been produced, must be sought for in other channels, and be determined by other means; as, by the general symptoms of disease, or by the history of the respective cases.

The morbid sounds of the respiration may, to avoid confusion and perplexity, be conveniently first divided into dry and moist sounds. By dry

sounds are intended those which arise from alterations of the calibre of the larynx, trachea, or bronchial tubes, from changes in the capacity, or from obstruction, of the pulmonary cells, or from roughening of the pleural surfaces. By moist sounds are meant those in which, either without, or in addition to, the alteration, obstruction, or roughening giving rise to the dry sounds, fluid secretion or effusion exists in the passages or cells, or air is mixed with fluid in the pleura.

2. Dry Sounds in Diseases of the Air-passages and the Lungs.

(a.) Larynx and Trachea.-If, from inflammatory engorgement of the lining membrane, from solid effusion upon the internal surface, or from fluid effusion beneath it, or if, in consequence of preceding ulceration, any contraction exist in the cavity of the larynx, or in the course of the trachea, which gives rise to constriction of the tube, and thereby impedes the free ingress and egress of air, a wheezing, whistling, or crowing sound is produced by the act of respiration. It is loud or slight, according to the amount of the obstruction, and to the power of the patient, and is generally louder during the inspiration than during the expiration. Of this nature is the harsh or crowing respiration existing in croup, and the wheezing of oedema of the glottis. A foreign body

fixed in the œsophagus, and pressing upon the trachea, or situated in the trunk of the airpassages itself, gives rise to similar sounds.

If a tumor, as an abscess, an aneurism, or a morbid growth,-exist in the vicinity, and exert such pressure upon the cartilaginous box, or tube as to produce obstruction to the breathing, the mechanical results are nearly the same; and the sounds which result from it, though they may vary a little in different cases, are also nearly the same. To the crowing convulsions or false croup of children, in which, though the cause is different, the mechanical effect is the same, so far as regards the sounds produced by respiration, as in laryngitis of the adult, similar observations may be applied

In each of these cases the noise is usually sufficiently obvious, and the evidence of obstruction is sufficiently clear, independently of auscultation. By the stethoscope we are enabled merely to say that obstruction exists. But the nature of that obstruction it telleth not. We may, indeed, case of a foreign

be able to state that, in the body, the cause of obstruction is fixed or moveable that it is now in one part and now in another but the feelings of the patient, if he be conscious, are usually amply sufficient to assure us of this.

Is, then, auscultation useless in diseases of, or in accidents occurring to, the larynx and trachea? It certainly is not. It is true that it merely indi